A former Howard County Public Schools substitute teacher has pleaded guilty to several counts of child pornography possession and child sex abuse.

In court Wednesday, Jeremy Sykes, 44, of Columbia, pleaded guilty to one count of sexual abuse of a minor and 18 counts of using a computer to depict a minor engaged in a sex acts. The counts cover two separate cases.

Sykes was charged in January after investigators determined he had uploaded child porn on two separate computers, one at his wife's house and one at Folly Quarter Middle School, where Sykes had worked as a long-term substitute teacher since October 2013. Sykes was banned from school property immediately after the charges were filed.

Howard County prosecutors said the pornographic images were all uploaded through Sykes' email address.

The plea deal cuts down the case against Sykes, who in May was charged with 14 more counts of sex abuse of a minor and 50 more counts of production of child pornography.

Officials searched Sykes' home in January and seized several electronic devices, which they said eventually revealed 50 images of pornography that Sykes had altered by using some students' yearbook photos to replace the faces of children in the porn photos.

Investigators said they identified 18 teen girls in the altered images, 14 of whom were Folly Quarter students. The four others Sykes knew outside of his role as a teacher, police said. Investigators said in May that they had not discovered any actual pornographic images of the students or found that any of the photos were distributed to anyone but Sykes.

Prosecutors said they'll seek a 45-year prison sentence for Sykes, of which they would suspend all but a little more than 16 years. Sykes will also have to register as a tier-3 sex offender.